D&C 24

The Lord instructed the Prophet Joseph Smith and Oliver Cowdery to -

"Magnify thine office...  (Doctrine and Covenants Section 24:3)

Regarding the meaning of magnifying ones office, President Joseph Fielding Smith said -

"Sometimes we speak loosely of magnifying our priesthood, but what the revelations speak of is magnifying our callings in the priesthood, as elders, seventies, high priests, patriarchs, and apostles.

The priesthood held by man is the power and authority of God delegated to man on earth to act in all things for the salvation of mankind. Priesthood offices or callings are ministerial assignments to perform specially assigned service in the priesthood. And the way to magnify these callings is to do the work designed to be performed by those who hold the particular office involved.

It does not matter what office we hold as long as we are true and faithful to our obligations. One office is not greater than another, although for administrative reasons one priesthood holder may be called to preside over and direct the labors of another. . .
We are called upon to magnify our callings in the priesthood and to do the work which goes with the office we receive. And so the Lord says, in the revelation on priesthood: 'Therefore, let every man stand in his own office, and labor in his own calling; . . . that the system may be kept perfect.' (D&C 84:109-110.)

This is one of the great goals toward which we are working in the priesthood program of the Church, to have elders do the work of elders, seventies the work of seventies, high priests the work of high priests, and so on, so that all priesthood holders may magnify their own callings and reap the rich blessings promised from such a course." (Joseph Fielding Smith, CR, October 1970, pp. 90-92.)

In magnifying ones office, the Lord said -

"Require not miracles, except I shall command you, except casting out devils, healing the sick, and against poisonous serpents, and against deadly poisons...."  (Doctrine and Covenants  Section 24:13)

Our priesthood office is not require miracles of the Lord, that is His choice.  But he does provide exceptions specifically in regards to giving blessings, healing the physically and spiritually sick.  But even then, the Lord counsels -

"And these things ye shall not do, except it be required of you by them who desire it..."  (Doctrine and Covenants Section 24:14)

The priesthood should always request the permission on request of the individual.